In the past the operations of loading and unloading of cargo have been performed manually, although the unloading of cargo has been performed by remote control signals for externally slung helicopter loads. Ground personnel have had to manually place the cable over the cargo hook, to enable cargo to be lifted by a hoist cable. In addition, in no known publicized instance has cargo been automatically unloaded without the application of an electrical or hydraulic signal. Signal control systems can be damaged, making necessary for the unloading operation to be manually performed. There may be hazardous environmental conditions in which both the loading and unloading operations should be performed without the presence of ground personnel at the loading platform. This may be particularly true at toxic waste sites and under other hazardous environmental situations. In both military and nonmilitary operations, helicopters need to pick up cargo from a hilly or wooded area and transport such cargo to another site. Many times the loading and unloading operations are hazardous because of the air currents from the rotor and wind gusts, for the tasks to be done entirely manually. In some operations, ammunition, weapons, toxic chemicals in containers need to be moved and transported from one site to another. It would be safer and quicker not to have ground personnel loading and unloading such load items manually. Presently, containerized toxic materials are loaded manually by ground personnel so they can be moved to a safe dumping area. It would be safer and less hazardous to human life if such cargo could be loaded and unloaded automatically without the aid of ground personnel.
Presently, Breeze-Eastern, Union, N.J., supplies the military with complex cargo hooks, capable of unloading the cargo load cable automatically with the application of a signal to a solenoid, within the cargo hook. A separate insulated, shielded wire is used to transmit the signal from a remote switch. The Breeze cargo hook is incapable of automatically loading the load cable. A typical 6000 Lb. capacity Breeze cargo hook requires, for release at dropping capacity, 22-28 VDC at 12 to 15 amperes, and a minimum release load of 7 Lbs. for 13/8" travel of the rotatable hook portion.
Cargo hooks made by Columbus McKinnon Corp., Amherst, N.Y. and by B. E. Wallace Products Corp., Exton, Pa., are strictly mechanical hooks with no automatic loading or unloading features.
In this invention, with or without a solenoid, the coupling device is capable of both loading and unloading a load cable automatically. Without a solenoid, the device is capable of performing both operations without the requirement of an electrical signal and still capable of safely transporting cargo.